Whales mourn if a family member is taken: scientists

Tasmanian scientists are examining the teeth of 100 whales and believe their research shows whaling impacts the mental health of other whales in the pod.

In February 1998 more than 100 sperm whales from three pods beached and died on Tasmania's north and west coasts.

Scientists are now sawing their teeth in half to find out more about the species.

The University of Tasmania's Mark Hindell says the teeth have provided vital information about the demographic structure of pods, and explained social behaviours.

"They [the teeth] are absolutely invaluable ... it underpins everything that we learn about these animals, they're kind of like gold," he said.

Associate Professor Hindell says some of the whales were over 60 years old and were all closely related, which could help explain why they stranded.

He says closely related pods have such tight bonds that when one whale strands, they all follow, because they don't want to leave the whale on its own.

"[Having the teeth is] quite unique because they were whole family pods and you don't get access to pods in any other way," he said.

"To study these animals in the wild, if they're still alive and swimming around, you just can't do it, so even if you went to do biopsies for skin samples you just can't do it, you never get the whole pod."

The CSIRO's Karen Evans says whale teeth are similar to tree rings.

"You can count those ridges and it basically gives you the age of the animal," she said.

Dr Evans says the teeth show that when a whale is taken from a pod, the rest of the whales go into mourning, which is detrimental to their health.

"What tends to happen is if one individual has stranded, the social bonds between that group mean that the rest of the group don't want to leave the area without that individual," she said.

"And because they don't want to leave the area it then puts them into danger."